Question TNT not exploding!

I've been googling this for hours and cannot find a solution. I have a Bukkit server with SkyBlock, and on the SkyBlock TNT can be placed and ignited, but when it explodes, no damage is done to the surrounding blocks. I have checked all the config files for TNT related stuff and found nothing. Also, the use-case is having dispensers drop tnt so they ignite and destroy blocks on a redstone timer.